Arc-lamp



G. M. LITTLE.

ARC LAMP. APPLICATION FILED NOV. 12. 1915.

1,333,665. PatentedMar.16,1920.

WlTNES SES: lN /ENTOR I Geo/ye 4/. [/7776 ATTORNEY waum/ ,W

: nLEcTnIc' AND MANUFACTURING COMPANY, .AconronATIoN' or; PENNSYLVANIA.

Ans-Lennie Toiill whom it may 0mm.-

"Be it known that L'Gilonen M: LITTLE, a

citizen ofthe United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania,have invented a new and useful Improvement in Arc-Lamps, of which "the following is aspecification;

I My invention relates to arcflamps and particularly. to such lamps as are provided with electrodes containing ingredients which,

When projected into the arc, render the arc flaming or highly luminous and engender I fumes which tend to attack and etch the globe surrounding the electrodes.

The obj t, of my invention is to provide an arc'lamp of the above-indicated character with means'for preventing'the fumes I, ,1 within the lampfrom attacking the glass or metal parts associated with the electrodes.

I accomplish this result byintroclucing into the arcing chamber a small amount of a vapor or a volatile'substance which,-Whenvolatilized, is capable of neutralizing the fumes, the neutralizing agent beingprcferably of such character that itlalso covers the surfaces exposed to the fumes witha' transparent protecting coating.

It has heretofore been customary to provide flamingarc lamps with a condensingcham berdisposed above and in connnunication with the arcing chamber and containing pieces of magnesia or other solid basic mation, but I prefer to employ organic amins, f

which are bodies of the ammonia type and e terial which are intended to absorb and neutralize any acid fumes that may be brought into contact with it during the operation of the lamp. I have discovered that the acid fumes may be much more effectively porous basic material which fills the globe and the condenser duringthe operation of the lamp reacts with the acid fumes substantially as fast as they are produced in the arc. v

A large number of substances are suitable for use according to my present inven- Which react as bases with respect to acids such as'those present in arcing fumes. Of these substances, I find that anilin 1s a 0on Application nia November 12.- 1915. "Serial 61,649.

' venientf and' effective material, and a few chamber-of a flaming arc'lanip, are sufiicient' to materially protectboth metal and glass from the etchinglefi'ect of the fumes. It is Gnome m. v LITTLE, OF-PiITTSlBURGH, mmsmjrmn, {issmoa .TO: wnsrmenousn desirable',ihowever, to'continue also the use 7 i of, the ordinary magnesia consumer.

Clition to-neutralizing the acid fumes pro- Vapors ofanilin and other amins, in adj-" duced' by the arc during thefirst few hours" I of iburning, operate to protect the exposed surfaces of the lamp in still another manner, by covering suchcsurfaceswith'an exceedingly thin coating which is solidified by the heat of the are into a solid varnish-like V and transparent layer. This-coating prot'ects the exposed lsurfaces by mechanically preventing'thej fumes from reaching them;

*Ordinary ammonia gas'operates like the organic amins mentioned above in neutraliz-" ing' the are l fumes," but, as ammonia forms 1 no permanent'protecting film'upon the ex= posed surfaces, I prefer to 'make use of anili-ir'orsom'ejother of the am1ns. Y One embod ment of my invention is lllUS-' tra ted in the accompanying drawing," the single'figure of which is aside vie-W, mainly I iii-elevation fb'ut partly I in section, showing: a flaming-arc lamp having my invention'ap pliedthereto.

The lamp comprises the globe 4, a condensing chamber 5 and'a casusual cooperating electrodes 1 and-2, an inner globe 3, an outer ing 6 for inclosing the operating mechanism of the 'lamp.- Disposed within the inner globe 3 is a pad 7 of asbestos or other ab;-

sorbent material which has been impregnated with anilin or other substance capable of evolving basic vapors and dropped into the globe While trimming the lamp. The absorbent pad is desirable but not absolutely necessary,- as the liquid may merely be pouredinto the globe.

The volatile neutralizing agents mentioned above are preferably used in confiection with the magnesiaconsumer ordi narilyused in lamps'of this character, but the volatile protecting agents may be used alone.

One advantage possessed by my volatile neutralizing agents, *in comparison with the ordinary magnesia consumer, is that the acid fumes developed when the lamp is 401.: forminga protecting coating; upon; the 7 sur-.

first started are immediately neutralized."

consumers absorb a considerable amount of moisture. from the. air. when the lamp is opened to be cleaned,- and the newly trimmed electrodesmay themselves contain: It therefore usually hap-;

some moisture. pensthat,.when the lamp is: first lighted, it

contains: a substantially moist atmosphere which assists the acid fumestin'attackmgthe' exposed surfaces oii glass and-metal. This effect canlobvionsly be only partially. prevented by the ordinaryblocks. otmagnesia V disposed, as is usual, in .a relatively inacces V sible corner ofthecondensing, chamber.

- Mypresent invention is not limited-to any specialconstruction of arclampor to the. use of. any specific protective substances eX-- cept as such limitations appear inthe ap penjdedclaims; V I I I cla m as my invention:

1. p In an. arc lamp,. a pair of; cooperating electrodes-and a globe surroundmgthe said electrodes and containing a fluid the vapor of- \vhich is capable of; forming; a protecting coatingupon the surfacesethat are exposed A mentally affects .the globe, of .means responto the *said 1 fumed.

'2 2.11: an arc lamp, a pair of cooperating electrodes and globe/surrounding the said electrode s and containing; a. fluid. the vapor of Fvvhich is cap able of-neutralizing the fumes produced by thearc and also capable of faces that are exposed Y to the said fumes;

3L In an arc lamp, a pair of coiipe'rating electrodes and a globe surroundmg the said capable When heatedof forming-an arcfume resistant coating upon the globe.

t. In an arc lamp, a pair of cooperating electrodes and a globe surrounding the said electrodes and containing anilin.

5. In an arc lamp, an arcing chamber,

electrodes and containing organic am-in:

electrodes therein, and absorbent means' sive to the burning operation of said light giving member for forming; a protective coating. on the globe I 8.In. a lamp, the combination With a mentally affects the globe, of means responsive to the burning. operation of light giving member for forminga' relatively durable protective coating on the: globe.

9. In a; lam the combination With a globe and a .li'g t-giving member that detrisive to theburningfoperation of saidlight giving. member for forminga transparent protective coating. on the globe.

In testimony whereof I have hereunto subscribedrmy name this 29th day of Oct,

' GEORGE ML LITTLE.

7 globeand a lightrgivingmember that detri 

